Lutidine Adducts of Co(II) & Ni(II) Dithiophosphinates

54-5

Di-(p-chlorophenyl)dithiophosphinato Derivatives of Fe(III), Co(III) & Ru(III)

623-62

Interstitial water chemistry and nutrients fluxes from tropical intertidal sediment

310-318Depth profiles of chlorinity, nutrients, pH and alkalinity in interstitial waters from high porosity, carbon rich sediment cores of Gorai creek (near Bombay) were studied in different seasons to evaluate temporal changes in relation to their concentrations in the overlying creek water. The high chlorinity creek water infiltrating in the bed after September, progressively pushed down the monsoonal low chlorinity water trapped in the sediment resulting in a well-defined chlorinity minimum at the intermediate depth which progressively mi grated downwards as the dry season advanced. In the presence of high concentrations of NO3--N throughout the core lengths, the occurrence of high Talk was attributed to the enhanced rate of surface microbial activity and its subsequent downward transport with chlorinity. The inorganic products (NO3--N, NO2- -N, NH4+-N, PO43--P) of aerobic oxidation of organic matter accumul ated in the 0-4 cm sediment section before their transport. The nature of NO3--N profile suggested its generation in the surficial sediment followed by utilization in the intermediate level with the consumption rate decreasing in the bottom sections. An intermediate maxima of NH4+-N and PO43-P prevailed in most cores which gradually shifted downwards with chlorinity. A continuous build -up of NH4+-N in the interstitial waters unlike other nutrients was evident. Markedly high N:P molar ratios in surficial sections suggested the removal of PO43--P from interstitial water. The fluxes of all nutrients were oriented towards the water column. Hence, the nutrients released in the surficial interstitial water were partly transported to the overlying water with a significant portion migrating into the sediment with chlorinity.</span

Behaviour of boron, calcium and magnesium in Purna and Auranga estuaries (Gujarat), west coast of India

46-50Ratios of B:Cl, Ca:Cl and Mg:Cl were generally within limit of river water at one end and seawater at the other. Percentage addition or removal (PA & PR) of B, Ca and Mg was calculated using the concept of the theoretical dilution line. High percentage of removal of B at low chlorinities indicated its rapid removal in the initial encounter of river water with seawater. On the contrary, Ca was preferentially added at low chlorinities. Addition decreased as the chlorinity increased and removal was observed near to seawater chlorinity. Mg was more conservative when compared to B and Ca

Mercury enrichment in sediments of Amba estuary

89-96 Concentrations of Hg, total organic carbon (TOC), Al, Fe and Mn were determined in sediment of the Amba Estuary between the mouth and the head over a distance of 24 km in December and May during 1997-2002. Temporal and spatial changes in metal concentrations appear to be due to sediment movement associated with tidal movements. The Hg concentration varies in 0.05 -2.66 µg g-1 range and the profiles of its variation indicate Patalganga River that opens in the Amba Estuary is a major source of anthropogenic metal to the estuary. Geoaccumulation index and enrichment factor support Hg contamination of the estuarine sediment to a varying degree. Hg is not significantly correlated with TOC, Al, Fe and Mn in these sediments. </smarttagtype

Flushing characteristics and pollution assessment of Purna River Estuary

94-98Tide dominated coastal plain Purna River Estuary was studied to evaluate its flushing characteristics and pollution status. The shallow estuary was generally well-mixed vertically with excellent flushing due to high seawater influx and strong tidal currents. The flushing time of pH and trace metal concentrations in water did not seem to have been grossly affected by the present wastewater inputs. Some influence was however observed on the dissolved oxygen content and BOD specially in the inner estuary

Boron-chlorinity relationship in western Bay of Bengal

183-185Significant scatter in B/Cl beyond the limit of experimental error indicates that the ratio is not truly constant. B/Cl maximum, centred around 100 m, appears to be influenced by colloidal and particulate matter while the maximum at 400 m appears to be due to the influence of Persian Gulf and Red Sea water and also due to the release of boron by oxidative degradation of organic matter. At 3000 m depth the ratio is typical of Antarctic bottom water

Base-line water quality of the river Narmada (Gujarat)

161-164Suspended solids, pH, chlorides, DO, BOD, PO -P, NO -N and NH -N were estimated at 12 stations along a 70 km stretch from the mouth of the river Narmada during March, May, June and August 1979. Tidal range of over 1 m observed at a point 52 km upstream was due to the piling up of fresh water, and some intrusion of sea water occurred at 44 km upstream in early June when riverine flow had decreased considerably. Significant penetration of saline water was observed only up to 20 km during March. The water column was well mixed vertically with the absence of any significant stratification. High pH of fresh water influenced the pH of the estuarine region which varied considerably over tidal cycles. The estuarine zone was characterized by high, tide dependant, suspended load which decreased appreciably in fresh water region. High overall DO and low BOD indicated the absence of gross organic pollution in the estuarine and riverine zones. NO -N decreased in the downstream direction while PO -P showed an increase; NH -N concentration indicated natural background levels

Pollution in river Par and its abatement

266-270Par River Estuary receives about 25,000 m3/day of effluent from a large chemical complex. The tidal effect at the present discharge point is weak and sufficient dilution water is not available except during spring tides. During monsoons, due to flushing, good water quality within the estuary is observed which, however, deteriorates after March when the river flow becomes negligible. The effluent does not mix well with sea water and flows downstream during the ebb tide. DO, BOD and pH show variation with the tidal stage. Flushing time computed employing tidal prism method is 1.4 tidal cycles while with fraction of fresh water method it is 4.4 days. Dye dispersion studies indicate that an appreciable fraction of the effluent would be washed to the sea during ebb tide if discharged about 3 km downstream